A policeman was killed last night after he was attacked while trying to break up a Boxing Day family row.

The officer - who has not been named - is believed to have been pushed down the stairs inside the suspect's house. He staggered out into the street where he collapsed and died.

Officers were called to a "domestic" in Wembley, North London. One neighbour said: "Police have been to the house three times in the past couple of months. There has been lots of rowing between the couple and we often hear a child crying. It's been terrible.

"My husband and I were watching TV today when we heard a commotion and a policewoman came to the door to say an officer had been killed. It is so shocking."

Another neighbour, who did not want to be named, said: "The street is full of rumours, from some people suggesting he was beaten up, or pushed down the stairs and hitting his head. However it happened it is a tragedy."

The officer's colleagues were devastated by his death. One said last night: "We get thousands of calls like this at Christmas when people have had too much to drink. It is a senseless waste that a row in a family has ended in the death of a policeman."

No knife or gun was used in the attack which happened in a cul-de-sac where houses sell for around £300,000.

Officers were called to the domestic dispute at around 5.45pm. A man was last night in custody after being arrested on suspicion of murder. Specialist officers were continuing to carry out a fingertip search of the house.